Definition of fission
1 : a splitting or breaking up into parts
2 : reproduction by spontaneous division of the body into two or more parts each of which grows into a complete organism
3 : the splitting of an atomic nucleus resulting in the release of large amounts of energy
fissionalplay \ˈfi-shə-nəl, -zhə-\ adjective
Recent Examples of fission from the Web
NASA’s interest in fission resurfaced after a 2010 study that looked at options for RTG systems.
At Livermore, Teller worked on his ultimate vision, the hydrogen bomb–a product of nuclear fusion, which creates much larger bombs than nuclear fission.
Despite divides, other groups remain optimistic concerning any fission within the LGBTQ community.
In the first months after the fission experiments became public knowledge, however, Einstein had not paid much attention.
As early as the spring of 1939, The Washington Post reported that nuclear fission could lead to weapons powerful enough to destroy everything over two square miles of ground.
The fuel, which contains plutonium and other products of nuclear fission, will remain radioactive for tens of thousands of years — time enough for a new ice age and other epochal events.
Visitors will be able to enjoy an evening of food, fun and fission during community information night on Wednesday, June 14, from 5 to 8 p.m., according to an announcement from plant operator Exelon Generation.
Some environmentalists include nuclear fission as well.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fission'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Definition of fission
: to undergo fission
: to cause to undergo fission
First Known Use of fission
FISSION Defined for English Language Learners
Definition of fission for English Language Learners
physics : a process in which the nucleus of a heavy atom is split apart
biology : a kind of reproduction in which a cell or body divides into two or more parts and each part grows into a whole new individual
FISSION Defined for Kids
Definition of fission for Students
1 : a method of reproduction in which a living cell or body divides into two or more parts each of which grows into a whole new individual
2 : the process of splitting an atomic nucleus with the release of large amounts of energy
Medical Definition of fission
1: a method of reproduction in which a living cell or body divides into two or more parts each of which grows into a whole new individual
2a: cleavage 2b: the splitting of an atomic nucleus resulting in the release of large amounts of energy—called also nuclear fission
Seen and Heard
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